Apparatus for manufacturing pigments



(No Model.) 2 Sheets-Sheet 1. P. L. BARTLETT.

APPARATUS PUR MANUFACTURING PIGMBNT.

110.415,185. I L; Patented Nov. 19, 1889.

P (N0 MOdGL) 2 Sheets-Sheet 2.

P. L. BARTLETT.

APPARATUS PUR MANUFACTURING PIGMENT. No. 415,185. Patented Nov. 19, 1889.

N. PETERS. PhoiLilhagl-.lphen Washmgtcn. l!A C.

AIO

UNTTED STATES PATENT OFFICE.

FRANK L. BARTLET', OF PORTLAND, MAINE.

APPARATUS FOR MANUFACTURING PIGNIENTS.

SPECIFICATION forming part of Letters Patent No. 415,185, dated November 19, 1889.

Application filed May 19, 1888. Serial No. 274,426. (No model.)

To all whom, it may concern:

Be it known that I, FRANK L. BARTLETT, a citizen of the United States, residing at Portland, in the county of Cumberland and State of Maine, have invented certain new and useful Improvements in Apparatus for Manufacturing Pigments; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to apparatus for the manufacture of paint-pigments direct from the ores of lead, zinc, sulphur, or ant-imony, or mixtures of these. Hitherto such pigments have been made by the following wellknown methods, namely: Zinc oxide has been made from the carbonate and oxide ores of zinc by mixing the ore in a iinely-pulverized state with equal weights of anthracite coal and blowing in air in the well-known \Vetherill hearths. Sulphide of zinc has also been converted into the oxide by this method after rst roasting the ore to drive off the sulphur. Certain impurities interfere with the successful working of this process, only pure high-grade ores being adapted to it, and no attempt was made to save the non-volatile metals, as copper, gold, and silver, when they happened to be present. The loss was also very large, as from eight to twelve per cent. of the metal was always left in the slag.

Sulphate-of-lead pigment was made by the Lewis-Bartlett process by oxidizing the ore in hearth-furnaces into a crude pigment and then relining it in a blast-furnace into a white ligment. In this process only pure galena was used, and no attempt was made to save gold or other precious metals if present. Some attempt has also been made in ordinary blast-furnace smelting to save such fumes as come over from smelting mixed ores; but the fumes thus saved were of dark color and fit only for resmelting into the metals.

The class of ores to which my present invention is particularly applied is known as complex ores. These ores are mixtures of zinc, copper, lead, silver, gold, antimony, and arsenic, either all together or two or more of them held in combination with sulphur, and termed sulphurets. The presence of zinc in these ores is considered by snielters as objectionable, since it causes loss of the precious metals in smeltiug. Moreover, such ores have to be carefully roasted to expel the sulphur before they can be smelted by the usual processes. In the present method of smelting there is not only loss of the precious metals when zinc is present, but the zinc itself is lost in the process.

My process is basedA upon the following facts or discoveries, believed to be hitherto unknown, namely: First, when complex sulphuret ores are smelted in the raw or natural state without previous roasting and with suitable fuel and'iiuxing material in a strong blast of air, the volatile elements-zinc,lead, and antimony-can be driven off in an atmosphere of sulphurous oxide, as oxides, sulphates, and oxysulphurets, or mixtures of these, to form valuable white pigment, while the silver, gold, and copper suffer slight loss and can be saved by drawing them through suitable openings in the bottom of the furnace; and, second, if the column of fumes of zinc, lead, or antimony, when coming from the furnace in a highly-heated state, is divided into a large number of small columns by being passed through closed passages externally cooled, the product is instantly rendered white and increased in body.

The object of my invention is to devise an apparatus by which complex and low-grade ores may be transformed in a single opera tion into pure white marketable pigment, while the precious metals which may be contained in the ores are saved with but tritling loss.

My invention consists of the apparatus hereinafter described and claimed, and is designed to carry'into effect a certain process for which my application for a patent is now pending.

rllhe apparatus consists of a shallow' waterjacketed furnace having tuyeres or blastpipes entering at the sides, an arrangement of tiles laid so as to form zigzag passages through which the fumes from the furnace pass, an auxiliary furnace for oxidizing the fumes after they pass through the tiles, a passage leading from this furnace back over the main furnace to a cooling-chamber con- IOO taining contracted passages extern ally cooled, and a settling-chamber connected with said cooling-chamber and with the bag-room.

In the accompanying drawings I illustrate the apparatus by which my invention is preferably carried into effect.

In the drawings, Figure 1 represents a side elevation ofthe furnaces. Fig. 2 is a longitudinal section through the same on the line Fig. 5. Fig. 3 is a perspective view of three assembled tiles used in the regenerating apparatus. Fig. 4 is a sectional view of four assembled tiles. Fig. 5 is a section through @c oc of Fig. 2. Fig. 6 is a section through Y Y of Fig. 2.

A represents a blast-furnace having waterjacketed sides and ends. Although I prefer to use a furnace of this description, an ordinary brick or stone furnace may be used. The furnace is comparatively shallow and has a length which is considerably in excess of its width, and in its side it has numerous tuyeres or air-blast holes b b, all pointing sharply downward. At the bottom of the furnace are tap-holes evel, which are nearly at the same level, the tap-hole e4 being slightly higher than the tap-hole e. An air-pipe K connects with the tuyeres Z9 andr extends along the side of the furnace, which is also provided with feeding doors or openings a Ct at its top.

Connected with the furnace A and forming part thereof is the regenerating or oxidizing furnace B, the opening or flue between the two being filled by the smoke consumer or regenerator M, which is constructed of the tiles shown in Fig. 3, laid in such a way that the gas in passing through it follows a zigzag passage and comes in frequent contact with the surfaces of the tiles. Each of these tiles consists of a central bar m, at each end of which are offsets or projections fm, extending laterally in three directions at right angles to each other and to the central bar. The tiles can thus be built up to form a mass of brick-work traversed by indirect passages, wherein the gas is brought in frequent con tact with the surfaces of the tiles.

The furnace B is 'provided with bridgewalls C2 C2, between which are grates c c.

Y Opening underneath the grates c c are various branches jj from the air-supply pipe J. An air-pipe I, situated at the top of vthe furnace, isprovided with branches I', some of which open into the space or Iiue between the furnaces B and A, while some enter the bridge-walls C2 of the furnace B and are there supplied with perforations by which the air from the pipe is discharged into the furnace B.

The regenerating or oxidizing furnace B connects with an antechamber C, from which a passage L leads over the furnace A to the top of the cooler E. By passing over the furnaccthe passage is kept continuallyh cated,

so that the fumes may enter the cooler E as highly heated as possible, for the purpose hereinafter stated.

chiefly designed.

tl The cooler E consists of a closed chamberhaving two horizontal line-sheets e3, one near its top and one near its bottom, these Hue-- sheets being' connected by vertical tubes c',

which open into the spaces above and below said flue-sheets. A partition 'e2 divides the space above the upper flue-sheet linto two parts, and into one of these spaces opensY the passage L, above described, and from the other leads the pipe G. The pipe K connects with the space surrounding the tubes just above the lower flue-sheet, while a pipe F enters the same space near its top. The pipe F connects with the pressure-blower F. The pipe G, which leads from the top of the cooler E, passes to a settling-chamber D, from which the pipe H leads tothe bag-room or dust-collecting apparatus.

g g are the inlet and outlet water-pipes of the water-jacket of the furnace A.

Dampers d CZ control the air-blast in the pipes'I I,jj, and K. 4

In carrying out my process I may make use of any simple ores which are capable of producing a pigment; but I prefer to use the complex or sulphuret ores, for the reason that they are low-grade ores of comparatively small value for smelting purposes, and when worked by my process they produce the best pigment. As will be hereinafter pointed out, the apparatus can be run so as to produce the pure oxide pigments or the mixture of oxides and sulphates, sulphurets, dac., before spoken of but since the latter product is the IOO most valuable and the most cheaply made, y

for the reasonthat it utilizes a large proportion of sulphur, I prefer to operate it with that end in view, and, in fact, it is for the manufacture of this product that the apparatus is When sulphuret ores are to be treated, the process is as follows, namely: The ores, crushed to the size of a pea, are mixed with about twenty-five to thi rtyper cent., byweight, of coke, charcoal, or other'fuel, together with a suitable amount of fluxing material, when the nature of the ore requires it. If the zinc or lead ores to be treated are not sulphurets, or if they do not contain at least ten per cent. of sulphur, crude sulphur or sulphuret of iron is added to bring itup to this proportion. The mixture is charged into the blast-furnace in a shallow layer. (In practice I do not put IIO in over eighteen inches of ore, the.) This furoxide gas. The non-volatile metals-such as gold, silver, and copper-will fuse and settle to the bottom of the furnace in the form of mattes, and as they. accumulate they are drawn off through the tap-hole e, while the earthy impurities-such as silica, alumina, bc-unite with the flux and form slag,which is drawn off through the tap-hole et, which is slightly higher in elevation than the tap-hole e. The Zinc, lead, and antimon y are partially volatilized direct and partly fused, settling to the bottom of the furnace with the non-Volatile metals and the slag. This fused mass forms a thin layer, upon the top of which the air from the tuyeres strikes as it comes downward obliquely.' The zinc, lead, and antimony which are in this fused mass are largely oxidized and carried upward with the fumes. By the use of a shallow layer in the furnace and the location of my tuyeres so that the blast may strike the layer of fused material I am enabled to reduce the amount of the volatile metals found in the slag as low as iive per cent. The zinc, lead, and antimony pass off in an atmosphere composed of the other products of combustion-such as sulphurous oxide, carbonic oxide, carbonio-acid gas, and free nitrogen, as oxides, sulphates, and oxysulphurets of the metals. These fumes and products of combustion, carrying along with them a certain amount of unconsumed carbon and raw ores and other impurities, irst meet the air-supply, which is blown in over t-he furnace, and pass through the smokeconsumer M, where theycome then in contact with the incandescent tiles, and where such impurities are wholly or partially oxidized. In passing through the smoke-consumer M the fumes also become diffused, and in this state they enter the furnace B and pass over the regenerating or oxidizing fires, which are kept up of light coke in one or more of the divisions of the furnace B. These fires are supplied with air from the pipe J, and air is also blown in through the perforated pipes I2, contained in the bridge-walls C2, mixing intimately with the fumes as they pass through the furnace. The effectof the regeneratingfire, the smoke-consumer H, and the air upon the fu mes is to reduce any portions of raw ore passing over from the furnace A and to regenerate the heat, which must be kept up to a high degree to insure the success of the process.

Sufficient air only is admitted to furnish oxygen for the formation of sulphides of lead, zinc, ttc., and not enough to form the sulphates and to decompose any unburned raw ore that may be driven over from the furnace A, as described. No excess of air is allowed to enter, since it would have a tendency to completely oxidize the metals, forming oxides, which are not so desirable as a product as the oxysulphurets. The dampers d enable the operator to completely control the air-blast, so that the fumes can be run in a full atmosphere of sulphurous oxide, or in a mixture of that and atmospheric air, as desired. It is desirable to keep the gas in which the fumes are suspended strongly sulphurous, so that the sulphates and sulphurets will form as freely as possible. The now partially-refined fumes pass over into the antechamber C, where the heavy impurities are deposited, thence through the passage L to the coolerE, where they pass downward through the flues e', which are cooled by the cold air from the blower passing around them to the bottom of the cooler, and thence upward and out through the pipe G.

I have found that the highly-heated fumes passing through contracted passages which are externally cooled are suddenly rendered white and freed from the dark-colored impurities which cling to them. This effect I understand to be due partly to the mechanical action of the gas passing through the small tubes or contracted passages and the agitation incident thereto, whereby the flakes of pigment into which it is first formed are broken up and the impurities released, and partly to the sudden change of temperature, which contributes to this result. This explanation may or may not be correct, and I do not base my claim on it, but on the fact as pointed out.

It will be observed that since the hot gas passes insides the tubes and the cold air from the pressure-blower passes on the outside of such tubes the gas is cooled at the same time the air is heated, both of which results are desirable. i

The fumes after leaving the cooler E pass through the pipe G to the settling-chamber D, where the speed of the current is so reduced that all the remaining impurities settle, the refined pigment being drawn by an exhaustfan or other suitable means to a bag-room or dust-collector.

It is evident that the apparatus herein described may be varied as to its details to a very considerable extent without departing from the spirit of my invention as set forth in the claims.

I do not wish to confine myself to the exact regenerating apparatus here shown, as any suitable means can be used for this purpose. After the furnaces are well started and the brick-work thoroughly heated through, I find that it is not always necessary to keep the fires in the regenerating-furnace in operation, the incandescerft tiles and the air-blast being sufficient to accomplish the desired result without the aid of the coke fires.

The refractory material between the main furnace and the oxidizing-furnace may be omitted, if desired.

In another application now pending I claim some of the features of the apparatus herein shown and described, said application filed March S, 1889, and numbered 302,519.

1. The herein-described apparatus for the manufacture of pigment, consisting of a blast- IOO IIO

furnace, a passage or flue leading therefrom, an oxidizing-furnace provided with means for heating the air supplied thereto in the line of said flue,a mass of refractorymaterial filling said flue between the main furnace and said oxidizing-furnace and having tortuous passages passing th rough it, and air-pipes for supplying air to said oxidizing-furnace, blastfurnaee, and to the iiue leading therefrom, substantially as shown.

2. The herein-described apparatus for the manufacture of pigment, consisting of a blastfurnace, a passage or flue leading therefrom, a mass of refractory material in the line of said flue having tortuous passages extending through it for the passage of fume, an oxidizing-furnace situated in the line of said flu e,fa cooling-chamber having numerous small lues for the passage of fume, a collecting and set- Vitnesses:

y S. W. BATES,

ROBERT A. Davis. 

